using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Net;
using System.Text;

namespace ConvertHelper
{
    public static class SendHelper
    {
        public static string DoPost(string url, string json, int timeout = 10000)
        {
            string responseString = "";//post返回的结果
            ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, err) => { return true; };
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
            HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
            req.Method = "POST";
            req.Timeout = timeout;
            req.Headers.Add("Accept-Encoding", "gzip, deflate");

            if (!string.IsNullOrWhiteSpace(json))
            {
                byte[] postBytes = Encoding.UTF8.GetBytes(json);
                req.ContentType = "application/json; charset=utf-8";
                req.ContentLength = Encoding.UTF8.GetByteCount(json);
                Stream stream = req.GetRequestStream();
                stream.Write(postBytes, 0, postBytes.Length);
                stream.Close();
            }
            else
            {
                req.ContentLength = 0;
            }
            var response = req.GetResponse();
            responseString = GetResponseBody((HttpWebResponse)response);
            return responseString;
        }

        private static string GetResponseBody(HttpWebResponse response)
        {
            string responseBody = string.Empty;
            if (response.ContentEncoding != null && response.ContentEncoding.ToLower().Contains("gzip"))
            {
                using (GZipStream stream = new GZipStream(response.GetResponseStream(), CompressionMode.Decompress))
                {
                    using (StreamReader reader = new StreamReader(stream))
                    {
                        responseBody = reader.ReadToEnd();
                    }
                }
            }
            else if (response.ContentEncoding != null && response.ContentEncoding.ToLower().Contains("deflate"))
            {
                using (DeflateStream stream = new DeflateStream(
                    response.GetResponseStream(), CompressionMode.Decompress))
                {
                    using (StreamReader reader =
                        new StreamReader(stream, Encoding.UTF8))
                    {
                        responseBody = reader.ReadToEnd();
                    }
                }
            }
            else
            {
                using (Stream stream = response.GetResponseStream())
                {
                    using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
                    {
                        responseBody = reader.ReadToEnd();
                    }
                }
            }
            return responseBody;
        }

    }
}